In U.S. Pat. No. 2,716,185 D. Burliuk and E. Rambusch devised a luminaire construction that featured a selectively titling luminaire that could be installed in a mounting ring either entirely from below a ceiling or entirely from above the ceiling. The luminaire has a finishing plate mounted to a ceiling that is apertured to admit a lamp and to allow the light to escape. This plate supports two housing members, the lower of which is adjustable about a vertical axis, allowing tilting of the lamp, while the upper is adjustable on the lower about a sloping axis. The upper part carries the lamp, wiring and a cooling structure. By reaching through the aperture in the finishing plate, a user can adjust the lamp housing parts about the respective axes so as to vary the slope of the lamp axis and its orientation about the vertical axis. This dual adjustability of the beam slope and orientation have largely been overlooked in modern lamps. Beam slope is adjustable by forming the lamp housing in two portions including a peripheral spherical upper portion that is trimmed to a 22.5 degree angle and a lower portion, also having a peripheral edge trimmed to 22.5 degrees, with the lower portion rotatable relative to the upper portion, being held in position with clips. By rotating the lower portion relative to the upper portion, the beam angle may be adjusted at radial angles ranging from 0 degrees to 45 degrees in a selectively tiltable manner. Moreover, once a selected angle is set, the fixture may be axially rotated about 360 degrees of the vertical axis so that the beam may be directed in any desired direction.
A selectable tilt, similar to the '185 patent is described in U.S. Pat. No. 6,152,571 where two angled plates surrounding a lamp and beam rotate relative to each other so that a selected angle of the beam relative to a flush mount may be set, where the selected angle is relative to the beam direction. In U.S. Pat. No. 7,303,327 S. Copeland and M. Thompson describe an LED in which the direction of the emitted light can be controlled by adjusting a portion of the housing and/or by controlling the orientation of the LED array within the housing. In. U.S. Pat. No. 8,029,158 J. Chen describes an LED light module that includes heat dissipating radial fins. Heat generated by the LED light is conducted from a flat portion of the LED to the fins for dissipation. Another such structure is shown and described in U.S. Patent Publ. 2012/0281409 to S. Patkus et al. In U.S. Pat. Nos. 8,042,973; 8,047,687; and 8,079,736 M. Inoue et al. describe use of multiple LEDs with multiple reflector sections within a tubular heat sink structure with fins extending in the axial direction. U.S. Patent Publ. 2012/0320577 shows a titling LED lamp structure that includes radial fins in the axial direction.
One of the problems of the tilting lamps of the prior art is that the radial swing of a mounted lamp housing can interfere with wiring or cabling in a ceiling that is installed subsequently in the vicinity of the housing. As the housing is rotated it can sometimes contact nearby wiring causing wear on the insulation of the wiring or, in extreme cases, shorting of the wiring or the lamp.